1. Field
The following description relates to a codebook that is used in a multiple-input multiple-output (MIMO) communication system.
2. Description of Related Art
Currently, researches are being conducted to provide various types of multimedia services and to support higher quality and higher speed of data transmission in a wireless communication environment. Accordingly, technology associated with a multiple-input multiple-output (MIMO) communication systems using multiple channels are in rapid development.
A MIMO communication system may include a base station and one or more terminals. In a downlink communication, the base station operates as a transmitter, and the terminal operates as a receiver.
The base station and the one or more terminals may use a codebook including a plurality of codeword matrices for quantizing a particular space. The plurality of codeword matrices may be generated according to a predetermined criterion and may be stored in the base station and the one or more terminals. The codebook may be used by the base station and the one or more terminals during wireless transmission/reception.
For example, in a downlink communication of a closed-loop MIMO communication system, a terminal may detect a channel formed between the base station and the terminal. The terminal may select a preferred codeword matrix from a plurality of codeword matrices included in a codebook based on the detected channel, and may provide the selected codeword to the base station. For example, the terminal may feedback information associated with the preferred codeword matrix to the base station. Using the codebook, the base station may verify a preferred codeword matrix based on the received feedback information. The base station may determine a precoding matrix based on the preferred codeword matrix and then precode one or more data streams using the preferred codeword matrix.